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1.
晚白垩世以来沿阿尔金断裂带的阶段性走滑隆升 总被引：2，自引：1，他引：2
年代学和沉积学特征表明,与印度板块约55MaBP以来沿喜马拉雅东、西构造结缝合带碰撞后青藏高原的阶段性隆升相对应,沿阿尔金断裂带阿尔金山地区亦发生阶段性走滑隆升,时间段大致为55～30MaBP、约20MaBP、约10MaBP和1～0.8MaBP.始新世-渐新世期间,阿尔金断裂大型左行走滑活动的发生,对中国西北大陆构造格架产生巨大的影响,不仅改造了古老的盆地和褶皱带,而且控制了新生代的走滑拉分盆地和两侧盆地的沉积速率,并对青藏高原的阶段性隆升和地壳物质东向蠕散起到调节作用. 相似文献
2.
酒西盆地晚新生代沉积物重矿物分析与高原北部隆升 总被引：24，自引：4，他引：24
沉积物的形成是地壳差异升降运动的物质记录.位于青藏高原北缘的酒西盆地晚新生代沉积比较敏感和全面记录了高原北部的构造运动和隆升过程.老君庙剖面晚新生代沉积物重矿物分析表明13 MaBP以来酒西盆地南部沉积物中重矿物具规律性变化;依据重矿物具规律性变化和沉积特征,揭示了青藏高原北缘晚新生代以来地壳运动经历了稳定期(13～8.26 Ma)、逐步阶段性隆升期(8.26～<4.9 Ma)和急剧强烈整体阶段性隆升期(>3.66～0 Ma)三个重大构造演化过程。 相似文献
3.
阿尔金断裂带是青藏高原自印度与欧亚大陆碰撞后向北扩展的前缘断裂,其新生代活动性对于研究青藏高原隆升与扩展过程和机制具有重要意义。近些年,运用热年代学、断裂几何学和运动学、沉积学、磁性地层学和地震学等方法对阿尔金断裂带的性质、组成结构、断裂活动时代、走滑断裂运动特征、走滑位移量和走滑速率等进行了细致的研究,而对阿尔金断裂带沿线受其控制的新生代沉积盆地的地层年代、沉积演化特征虽然也有一定研究,但往往仅限于单个盆地,缺乏对沿线盆地整体的对比认识,造成对阿尔金断裂带走滑起始时间及阿尔金山的隆升历史存在不同的认识。本文对近二十年来阿尔金断裂带沿线新生代沉积盆地的磁性地层年代与沉积相演化的研究进展进行综述,建立阿尔金断裂带沿线盆地新生代沉积序列和年代框架;辅助热年代学等资料,提出阿尔金断裂带的三阶段演化模型:始新世-中中新世,阿尔金断裂带以大幅度的走滑运动为主,同时伴随着阿尔金山小范围的隆升;中中新世开始,阿尔金山开始大规模的隆升,伴随着较少量的走滑运动;晚中新世以来,阿尔金断裂带构造活动加强。 相似文献
4.
阿尔金断裂带东南缘含油气盆地群的形成演化 总被引：16，自引：0，他引：16
沿阿尔金断裂带东南侧发育六个中、新生代的含油气盆地，盆地的边缘或盆地内部发育一系列的近东西走向、与阿尔金断裂锐角相交的断裂，该组断裂对盆地的隆坳格局和地层分布具有控制作用，盆地具有箕状结构或不对称结构特点。沿阿尔金断裂带方向，保罗系、白垩系、古近系、新近系的厚度和沉积特征在时空上呈有规律性变化，显示了阿尔金断裂带时、空活动的差异性。根据侏罗纪盆地在阿尔金断裂带两侧的展布特征和柴达木盆地西部发育的鼻状构造及其沉积演化特征，推断阿尔金断裂带中、新生代经历了多期不同方向的走滑运动。 相似文献
5.
利用卫星重力异常研究中国西部岩石圈构造，发现中国西部壳内存在规律、清晰的平行线状排列盆山构造。自北而南是：额尔齐斯盆地带、北准噶尔隆升带、天山北盆地带(或天北盆地带)、天山隆升带、淖毛湖一乌力吉盆地带、天山南盆地带(或天南盆地带)、库鲁克塔克一北山隆升带、阿尔金山一祁连山北盆地带(或塔南盆地带)、西昆仑一阿尔金一祁连山隆升带以及柴达木盆地带和藏南盆地带。壳内盆地带主要形成于印支一燕山期强烈的挤压褶皱带内。喜马拉雅期，在印度板块自南西向北东的俯冲作用下，使婆罗科努山一察布查尔山一阿拉沟山一额尔宾山一霍拉山等山系横向隆升，和天山山脉一起，将新疆地区分割成伊宁盆地、准噶尔盆地、吐哈盆地和塔里木盆地，形成当今新疆地貌。研究表明，上述横向隆升山脉和其他北西一南东向新构造，在岩石圈地幔中均有相应的卫星重力异常，推测新构造运动的动力来自岩石圈地幔。对青藏高原的研究表明，青藏高原以雅鲁藏布江断裂、班公湖一怒江断裂、澜沧江和金沙江断裂等一系列相互平行的断层和其夹持的条形地块为特征，表层构造与壳内构造不符。这些条形构造和青藏高原地壳向东南的逃逸构造仅发生在上地壳。研究还表明印度板块俯冲到地幔仅发生在西藏西南部。在JJI西一藏东存在南北向的稳定地块，阻挡了印度板块向青藏高原俯冲的进程。从这项研究中得到启示，西部寻找油气资源应考虑：①不要局限于新生代盆地；②研究盆地的构造背景要考虑深部构造的控制；③基础研究对寻找油气资源能发挥重要的预测作用，可以为寻找古生代、中生代油气田提供线索，为部署工作提供参考。尤其应对天北盆地带、天南盆地带、塔南盆地带、柴达木盆地带，以及藏南盆地带的深部整体面貌及它们对地表构造的控制作系统的调查研究。 相似文献
6.
青藏高原2.8Ma来的环境演化及其对构造事件响应 总被引：2，自引：2，他引：0
本文根据青藏高原中部错鄂湖深钻研究的最新成果,结合东部若尔盖盆地湖泊沉积物记录,探讨了青藏高原2.8Ma以来的环境演化过程和高原构造隆升运动对环境演化的影响。初步研究显示:大约2.8MaBP错鄂湖构造成盆;2.6MaBP左右孢粉组合、粒度特征、岩性变化等均记录了一次强烈的构造隆升运动;2.6Ma~0.8Ma时段,高原可能处于一种整体隆升过程中的相对夷平阶段;若尔盖古湖揭示了0.9MaBP来的3次构造隆升运动,反映了高原环境演变的三个阶段;和黄土底界相当的错鄂湖沉积记录显示并未干旱的特征;黄土旺盛堆积时期(L15、L9、L6)高原湖泊记录的气候特征为偏湿气候。 相似文献
7.
阿尔金断裂东段的构造转换模式 总被引：1，自引：0，他引：1
大型走滑断裂控制着青藏高原的变形,众多学者通过阿尔金断裂来探索青藏高原北部的构造变形过程。基于野外调查和前人的研究结果可知阿尔金断裂的滑动速率在肃北—疏勒河口段表现为三联点两侧的突降,祁连山西段的逆冲和走滑断裂吸收了阿尔金断裂的左旋位移。由于祁连山内部次级断裂活动性的增强,现存阿尔金断裂连续地表破裂终止于酒泉盆地西侧,但位于其东侧的断裂系仍属于阿尔金断裂。在Kohistan岛弧与欧亚板块碰撞之后,青藏高原沿阿尔金断裂曾发生滑动速率近一致的侧向挤出,断裂两侧此时并未发生明显的隆起。随后东昆仑造山带和祁连山造山带的先后大规模隆升,高原的北东向挤出迅速减弱。阿尔金断裂北东向挤出能力与东昆仑造山带和祁连山造山带的隆起存在明显的耦合作用。 相似文献
8.
晚新生代温泉沉积盆地，是青藏高原腹地在南北向挤压、东西向伸展的构造背景下，沿南北向边界走滑断层，经边界正断层和内部张剪断层的进一步发展而形成的近南北向单断单剪楔形半地堑活动沉积盆地。它可能代表了晚新生代青藏高原第三期强烈挤压隆升事件，是侧向向东剪切挤出的结果。笔者以盆地充填序列和TL、ESR测年资料为主要依据，推测唐古拉山在300～250ka前后全面进入冰冻圈；而以温泉活动沉积盆地为代表的中更新世晚期(224．0～150．2ka)的冰碛一冰水堆积则对应于青藏高原第三期隆升的断陷盆地发育阶段；中更新世晚期一晚更新世中期(144．0～56ka)为湖相沉积；晚更新世中期至今(35～0ka)对应于高原缓慢隆升与夷平发育阶段。长江溯源在35ka切割通天河盆地，形成通天河；而在16kat浸蚀切穿雁石坪一温泉兵站峡谷，形成布曲河。 相似文献
9.
新生代龙门山前盆地和盐源盆地是青藏高原东缘龙门山－锦屏山冲断带内及前缘地区发育和保存最好的新生代沉积盆地，本次以地层不整合面和ESR测年资料为主要依据，将该区新生代构造地层序列划分为5个构造层序，即TS1（65－55Ma)、TS2(40-50Ma)、TS3（23－16Ma)、TS4(4．7-1.6Ma)和TS5（0．74－0Ma)，据此将青藏高原东缘新生代构造变形和隆升事件划分为5期，其中TS1与喜马拉雅地体和拉萨地体拼合事件相关，TS2与印亚碰撞事件相关，TS3与青藏高原第一次隆升事件相关，TS4与青藏高原第二次隆升事件相关，TS5与青藏高原第三次隆升事件相关。 相似文献
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青藏高原形成和演化过程中经历的构造活动,在高原的盆地中均有相应的沉积记录。柴达木盆地位于青藏高原北部,盆地新生界地层详细地记录了这些构造-沉积响应。对野外剖面和钻井岩心的新生界沉积物进行了多方面研究,其结果显示,柴达木盆地保存了青藏高原北部三个阶段的构造活动信息:①E1+2的红色粗碎屑沉积物指示了始新世早期的强烈活动构造背景,沉积记录具有低ZTR指数和低重矿物稳定指数的特征,记录了全盆地范围内的造山活动和构造隆升事件,是印度-欧亚板块碰撞所致的远程响应。在这次广泛的大面积的造山活动后,区内迅速遭受剥蚀、夷平,自中-晚始新世时期起,接受沉积。因而此时柴达木盆地与可可西里盆地、乃至塔里木盆地为连通的湖盆体系。②阿尔金山前N1和N21的粗碎屑沉积物记录了渐新世-早中新世阿尔金山的构造隆升事件,而柴北缘和柴西南的大范围三角洲-湖泊细粒沉积物,具有较高的重矿物稳定指数,反映了平静的构造背景,与阿尔金断裂快速走滑以及盆地总体稳定向北推移的时间相对应。大量的侧向走滑活动消减了来自印度板块的挤压应力,使得柴北缘和柴西南的沉积源区（即祁连山和东昆仑造山带）处于构造平静期。③中中新世以来全盆地向上变粗的粗碎屑沉积物,具有较低的重矿物稳定指数,记录了青藏高原北部整体强烈的地壳缩短、加厚和快速构造隆升事件。此外,综合物源分析显示,柴达木盆地新生代沉积源区性质随时间并没有发生明显的改变。 相似文献
11.
Guboglo M. N. 《GeoJournal》1980,4(1):53-58
International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen. 相似文献
12.
Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth
B. P. Kondratyev 《Astronomy Reports》2017,61(8):709-714
It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T 3 = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″. 相似文献
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Chronological analyses of correlations between certain global repeating events (mass extinctions of marine organisms, meteorite impacts, and flashes in the frequency of geomagnetic reversals) during the Phanerozoic Eon and the motion of the solar system in the Galaxy are presented for five rotationally symmetrical models for the regular Galactic gravitational field. Thirteen of sixteen mass-extinction events can be described by a repetition interval of 183±3 million years. This is in agreement with the anomalistic period (interval between two subsequent passages of the Sun through the apocenter of its Galactic orbit) in the model of Allen and Martos. The positions of the minima and maxima in Gaussian functions approximating the frequency distribution for geomagnetic reversals also agree with the times of passage of the Sun through the apocenter and pericenter, respectively, of its Galactic orbit in this model. The maximum in the distribution of the deviations of the dates of mass extinctions from the nearest dates of impacts of large, crater-forming bodies is close to zero, providing evidence that many such events are correlated. As a rule, extinctions follow impact events. The impacts of large bodies have occurred most often when the solar system passes through the Galactic plane, while mass extinctions occur more often at some distance from the Galactic plane (about 40 pc). As a rule, intervals of increases in the frequency of geomagnetic reversals coincide with dates of impacts of large bodies. At the same time, these intervals do not show a clear correlation with the dates of mass extinctions. The intensity of mass extinctions, like the energy released by impacts, is consistently higher in periods when the Sun is moving from the apocenter toward the pericenter of its orbit, than when it is moving from the pericenter toward the apocenter. Thus, there is evidence for a variety of relationships between repeating global events in the Phanerozoic and the motion of the Sun in the Galaxy. Long-period variations in the frequency of geomagnetic reversals are correlated with the orbital motion of the Sun, and increases in the frequency of geomagnetic reversals are correlated with impacts. Mass extinctions are correlated with the impacts of large bodies, whose motions may have been perturbed by clouds of interstellar material concentrated toward the Galactic plane and by the shock front associated with the Perseus spiral arm, through which the solar system passes. The velocity of the Sun relative to the spiral pattern is estimated. 相似文献
15.
位于华北和扬子两板块碰撞带中的苏鲁榴辉岩形成的温压条件不但是超高压，而且是高温。榴辉岩的PTt轨迹表明其为陆-陆磁撞俯冲带的产物。榴辉岩的区域性围岩花岗质片麻岩为新元古代同碰撞期花岗岩，榴辉岩及其他直接围岩皆呈包体存在于其中，并见新元古代花岗岩呈脉状侵入榴辉岩包体中。区域性围岩新元古代花岗岩的锆石中发现有柯石英、绿辉石等包裹体，表明新元古代花岗岩的组成物质也经受过超高压变质作用，且榴辉岩与围岩新元古代花岗岩的锆石U-Pb体系同位素年龄基本相同。但新元古代花岗岩所记录的变质作用和变形作用期次（或阶段）却少于榴辉岩。椐上述可得如下推断：超高压榴辉岩与新元古代花岗岩岩浆是同时在碰撞带底部（俯冲板块前部）形成的；榴辉岩的第一折返阶段是由新元古代花岗岩岩浆携带上升的，其第二折返阶段是和新元古代花岗岩一起由逆冲及区域性隆起而上升，遭受剥蚀。 相似文献
16.
某高速公路下伏煤矿采空区稳定性分析 总被引：10，自引：0，他引：10
在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。 相似文献
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摩擦桩基桩土间极限摩阻力取值问题探讨 总被引：1，自引：0，他引：1
通过对广珠东线高速公路横沥大桥的试桩及土体的工程地质条件分析,总结出影响摩擦桩基桩土间极限摩阻力取值的一般问题以及解决问题的方法和措施。 相似文献
19.
The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads 总被引：3，自引：1，他引：2
Clemente Irigaray Francisco Lamas Rachid El Hamdouni Tomás Fernández José Chacón 《Natural Hazards》2000,21(1):65-81
In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning. 相似文献
20.
The structure of the eastern Pyrenees consists mainly of south-directed thrusts involving basement and cover rocks. An antiformal stack developed by the piling up of basement thrust sheets which outcrop in the Axial zone. These structures account for a thin-skinned thrust model rather than a vertical fault model in which the Axial zone would be essentially autochthonous, and the North-Pyrenean fault the axial plane of a fan thrust system. New data from the Eastern Pyrenees and the thin-skinned model suggest that(1) the structure east of the Pedraforca nappe is similar to that of the Central Pyrenees; (2) the cover rocks of the South-Pyrenean units and of the Axial zone-after restoration—built up a northwards-thickening prism consistent with the existence of a unique Pyrenean sedimentary basin during Mesozoic time; (3) the Axial zone is only a complex antiformal stack developed as a part of South-Pyrenean system related to the Paleogene thrusting-tectonics. The Axial zone palaeogeographic area had no special meaning during Mesozoic time. 相似文献